To analyze the deformation and stability characteristic of cutting slope containing weak interlayer in excavation process，the three-dimensional geological model of the slope with weak interlayer was constructed using the ANSYS software，the model was then imported the FLAC^3D，the excavation and support process of slope was simulated.The safety factor of the slope was solved by the self-defined strength reduction method，and the excavation deformation and stability characteristic of the cutting slope with weak interlayer were analyzed. The simulation results show that the deformation of slope increases gradually with the increase of the excavation depth. The deformation increases abruptly near the weak interlayer. The whole slide of the slope is induced by the local sliding of the weak interlayer. Moreover' the deformation can be restrained using the strengthen method of anti-slide pile，ensuring the overall stability of the slope.